1998 Volume 61 Issue 4 Pages 297-303
The enzyme complex 3β-hydroxysteroid dehydrogenase (3β-HSD) is involved in the biosynthesis of all classes of active steroids. It is known that the enzymatic activity of 3β-HSD is present not only in classical steroidogenic tissues, but also in many peripheral tissues including cardiac tissue. To determine whether 3β-HSD is present in rat non-steroidogenic tissues, we examined cardiovascular tissues including the ventricle, atrium, aortic arch, abdominal aorta, and inferior vena cava by immunohistochemistry and Western blotting using polyclonal antibody raised against a synthetic peptide of human placental 3β-HSD.
By Western blotting, protein bands immunoreactive for anti-3β-HSD were detected at molecular weights of 42 and 37kDa in both the ventricle and atrium, whereas only a 37kDa band was recognized in both the aortic arch and abdominal aorta. By immunohistochemistry, immunoreactivity for 3β-HSD was detected in both the ventricular and atrial cardiocytes, while immunostaining was also found, though faintly, in the smooth muscles of the aortic arch, abdominal aorta, and inferior vena cava.
These results suggest that cardiocytes may synthesize the steroidogenic 3β-HSD enzyme.
